CN113518980B - System and method for flexible optical interconnect in a data center - Google Patents
System and method for flexible optical interconnect in a data center Download PDFInfo
- Publication number
- CN113518980B CN113518980B CN201980093429.0A CN201980093429A CN113518980B CN 113518980 B CN113518980 B CN 113518980B CN 201980093429 A CN201980093429 A CN 201980093429A CN 113518980 B CN113518980 B CN 113518980B
- Authority
- CN
- China
- Prior art keywords
- switch
- optical
- fiber optic
- optical transceiver
- switches
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 275
- 238000000034 method Methods 0.000 title claims description 14
- 239000000835 fiber Substances 0.000 claims abstract description 214
- 238000004891 communication Methods 0.000 claims abstract description 22
- 230000008878 coupling Effects 0.000 claims description 42
- 238000010168 coupling process Methods 0.000 claims description 42
- 238000005859 coupling reaction Methods 0.000 claims description 42
- 230000007246 mechanism Effects 0.000 claims description 6
- 239000013307 optical fiber Substances 0.000 description 29
- 239000010410 layer Substances 0.000 description 9
- 230000002776 aggregation Effects 0.000 description 4
- 238000004220 aggregation Methods 0.000 description 4
- 239000012792 core layer Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 208000002447 Macrophagic myofasciitis Diseases 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 241000723418 Carya Species 0.000 description 1
- 101000798940 Gallus gallus Target of Myb protein 1 Proteins 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000003012 network analysis Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
- G06F13/38—Information transfer, e.g. on bus
- G06F13/40—Bus structure
- G06F13/4004—Coupling between buses
- G06F13/4022—Coupling between buses using switching circuits, e.g. switching matrix, connection or expansion network
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0005—Switch and router aspects
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
- H04Q11/0005—Switch and router aspects
- H04Q2011/0007—Construction
- H04Q2011/0018—Construction using tunable transmitters or receivers
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Mathematical Physics (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)
Abstract
One embodiment described herein provides a communication system. The communication system can include: a first switch comprising one or more optical transceiver modules; and a plurality of individual fiber optic cables coupled to respective optical transceiver modules on the first switch.
Description
Technical Field
The present disclosure relates generally to data center designs. More particularly, the present disclosure relates to designing optical interconnections among switches in a data center.
Background
The rapid increase in computing needs of cloud users continues to drive the computing power of cloud servers, thereby increasing the speed and scalability requirements of data centers. A typical data center may be a pool of resources (e.g., computing, storage, and network resources) interconnected using a communication network. Data center networks play an important role in data centers because it interconnects all data center resources.
Data center networks need to be scalable and efficient in order to connect thousands or even hundreds of thousands of servers. Key characteristics of a data center network can include bandwidth, size, and latency. Designers of data center networks often pursue large-scale, low-latency, and low-cost goals. Designing a large-scale data center network while keeping costs and delays low can be a challenge.
Disclosure of Invention
One embodiment described herein provides a communication system. The communication system can include: a first switch comprising one or more optical transceiver modules; and a plurality of independent fiber optic cables coupled to respective optical transceiver modules on the first switch, thereby allowing the first switch to be coupled to a plurality of other switches in the communication system via at least the plurality of independent fiber optic cables.
In variations on this embodiment, the respective optical transceiver module can include one or more of the following: based on SN TM An MDC-based optical interface, and a multi-fiber push-pull (MPO) optical interface.
In another variation, the respective optical transceiver module can include a plurality of SN or MDC based interfaces, and the respective fiber optic cable can include SN or MDC based connectors for coupling the respective fiber optic cable to the optical transceiver module, respectively.
In another variation, the respective optical transceiver module can include an MPO optical interface, and the respective fiber optic cable can include an MPO connector or duplex LC connector for coupling the respective fiber optic cable to the optical transceiver module.
In another variation, the respective optical transceiver module can include an MPO optical interface, and the respective fiber optic cable can be coupled to the MPO optical interface via an MPO converter that converts the higher fiber count MPO interface to a lower fiber count MPO interface.
In variations on this embodiment, each of the plurality of independent fiber optic cables can be coupled to a different switch in the communication system.
In a variation on this embodiment, the corresponding switches in the communication system can have an input/output (I/O) capacity of 256×50 Gbps (gigabits per second) or 512×50 Gbps.
In another variation, the respective optical modules can have a speed of 200 Gbps or 400 Gbps.
In a variation on this embodiment, the first switch can includeNA plurality of optical transceiver modules, and each optical transceiver module is capable of being coupled toMAnd (5) independent optical cables. The first switch being coupleable to a communication systemM×NAnd other switches.
In another variation, the communication system can include a two-stage switch. The corresponding port usage triplets of the first switch on the first stage and on the downlink of the first switchi 1 , j 1 , k 1 ) Marking by a mark, whereini、j、kRespectively representing the switch number, the optical module number and the port number. Port [ ]i 1 , j 1 , k 1 ) Port coupled to an uplink of a second switch belonging to a second stagei 2 , j 2 , k 2 ) Whereini 2 = j 1 * M + k 1 ，j 2 = i 1 %MAnd (2) andk 2 = mod(i 1 , M)。
one embodiment can provide a coupling mechanism for coupling among switches in a data center network. The coupling mechanism can include a plurality of independent fiber optic cables coupled to respective optical transceiver modules on respective switches, thereby allowing the respective switches to be coupled to a plurality of other switches in the data center network.
One embodiment can provide a method for coupling among switches in a data center network. The method can include: selecting a switch; coupling first ends of a plurality of individual fiber optic cables to respective optical transceiver modules on a selected switch; and coupling a second end of the plurality of fiber optic cables to a plurality of other switches in the data center network.
Drawings
FIG. 1 illustrates an exemplary network infrastructure of a data center.
Fig. 2A and 2B show an exemplary interconnection among two different stages of switches according to the prior art.
Fig. 3A illustrates an exemplary interconnection among switches according to one embodiment.
Fig. 3B illustrates an exemplary interconnection among switches according to one embodiment.
Fig. 4 illustrates an exemplary network with two stages of switches according to one embodiment.
Fig. 5A illustrates an exemplary optical interface of an optical transceiver module.
Fig. 5B shows an exemplary optical interface configuration of an optical module according to the prior art.
Fig. 5C illustrates an exemplary output configuration of an optical module according to one embodiment.
Fig. 5D illustrates an exemplary output configuration of an optical module according to one embodiment.
Fig. 6A illustrates an exemplary arrangement of a plurality of fiber optic cables according to one embodiment.
Fig. 6B illustrates an exemplary arrangement of a plurality of fiber optic cables according to one embodiment.
Fig. 7A illustrates an exemplary output configuration of an optical module according to one embodiment.
Fig. 7B illustrates an exemplary output configuration of an optical module according to one embodiment.
Fig. 8A illustrates an exemplary arrangement of a plurality of fiber optic cables according to one embodiment.
Fig. 8B illustrates an exemplary arrangement of a plurality of fiber optic cables according to one embodiment.
Fig. 9 presents a flowchart illustrating an exemplary process for establishing a data center network, in accordance with one embodiment.
Like reference symbols in the various drawings indicate like elements.
Detailed Description
The following description is presented to enable any person skilled in the art to make and use the embodiments, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the disclosure. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
SUMMARY
Embodiments described herein address the technical problem of providing efficient and flexible optical interconnections among switches in a data center. More specifically, by implementing multiple parallel fiber outputs on each individual optical module, some embodiments increase the number of independent ports on each switch without modifying the internal structure of the switch or increasing the count of optical modules on the switch. In some embodiments, the optical module may conform to a standard form factor, such as a quad small form factor (QSFP) or an eight small form factor pluggable (OSFP), and may be capable of coupling the optical module to a plurality of optical cables using various types of optical interfaces, each optical cable corresponding to a switch port. In some embodiments, the fiber optic cables from a particular switch on a particular switch stage can be arranged such that they are coupled to other individual switches on the next stage, one switch per fiber optic cable. Given a configuration provided withNA switch of individual optical modules, wherein each optical module is coupled toMA parallel output optical cable, the switch being capable of being coupled to at mostM×NAnd other switches.
Optical interconnection of data centers
FIG. 1 illustrates an exemplary network infrastructure of a data center. In fig. 1, the data center network 100 can include three layers of network switches, namely an access layer, an aggregation layer, and a core layer. The server is connected to the switches in the access stratum. The aggregation layer switch interconnects the plurality of access layer switches. The aggregation layer module can also provide various important services such as content exchange, firewall, secure Socket Layer (SSL) offload, intrusion detection, network analysis, etc. All aggregation layer switches are interconnected by core layer switches. The core layer switch is also responsible for connecting the data center to a network (e.g., the internet) external to the data center. To meet the increasing user demand for computing power, data centers should include a large number of interconnected high-performance servers.
The hardware modules used to form a data center network (e.g., data center network 100 shown in fig. 1) can include electrical switches, optical transceiver modules (or simply optical modules), and fiber optic cables. Current data centers typically implement a 100 Gbps (gigabit per second) network in which the electrical switch chips have an input/output (I/O) capacity of 128 x 25 Gbps or 256 x 25 Gbps and the optical transceiver modules have a 100 Gbps speed. The Network Interface Card (NIC) of each server can have a speed of 25 Gbps or higher. The next generation data center may implement a 400 Gbps network in which the switch chip has an I/O capacity of 256×50 Gbps or 512×50 Gbps and the optical transceiver module has a speed of 400 Gbps. The NIC speed of the server in the next generation data center can reach 100 Gbps.
For high-speed (e.g., 100 Gbps and beyond) data center networks, optical interconnections (e.g., optical transceivers and fiber optic cables) may be necessary to achieve interconnections among switches and coupling between access layer switches and servers. For large-scale networks, it is desirable to have as many switch ports as possible. However, speed mismatch between the switch chip I/O and the optical transceiver can often result in a reduced number of ports on the switch, which can in turn limit the size of the data center network. For example, the switch chip I/O can include 512 electrical channels, with each channel operating at 50 GHz. On the other hand, the optical transceiver module may have a speed of 400 Gbps, meaning that up to 8 electrical channels would need to be combined onto a single optical transceiver, which is often coupled to a single optical cable to act as a single switch port. Thus, instead of providing 512 switch ports, the switch module can only provide up to 64 switch ports.
One possible solution for increasing the port count on a switch is to increase the number of switch chips included in the switch. By cascading multiple switch chips, one can increase the total port count of the switch. However, such solutions can be expensive and can also increase network latency.
Another solution is to reduce the speed of the optical transceivers and use a much larger number of transceivers to serve each switch, thereby equally increasing the number of ports on each switch. Fig. 2A and 2B show an exemplary interconnection among two different stages of switches according to the prior art. In fig. 2A, each switch is equipped with one optical module with a single fiber optic cable output. More specifically, the upper level switch 202 is equipped with a high-speed optical transceiver module 204 (e.g., 400G optical module for 400G networks), and the lower level switch 212 is equipped with a high-speed optical transceiver module 214. The output of each optical module is a single fiber optic cable (e.g., fiber optic cable 206). As one can see, the switches at each stage can be coupled to only a single switch at a different stage, since each switch has only one port for each link (e.g., uplink or downlink). Note that here each switch actually includes both uplink and downlink. In the figures, only one link (uplink or downlink) is shown for simplicity. On the other hand, in the example shown in fig. 2B, the uplink or downlink of each switch is equipped with two optical modules with reduced speed. For example, instead of 400G optical transceivers, each switch can be equipped with two 200G optical transceivers. More specifically, the downlink of the upper level switch 222 is equipped with optical transceiver modules 224 and 226, while the uplink of the lower level switch 232 is equipped with optical transceiver modules 234 and 236. Similar to the example shown in fig. 2A, each optical transceiver module has a single output fiber optic cable. For example, the optical module 224 has an output cable 228 and the optical module 226 has an output cable 230. As a result, each switch now has two switch ports that can be connected to two other switches. In the example shown in fig. 2B, each of the two superior switches (e.g., switches 222 or 242) can be coupled to two inferior switches (e.g., switches 232 and 252). The scale of the network shown in fig. 2B is twice as large as the example shown in fig. 2A.
However, it may not be cost effective to increase the number of optical transceivers without increasing the network speed, as the cost per bit of the optical module increases. Furthermore, the increased number of optical transceivers can also lead to an enlarged size of the switch box, which is undesirable in a data center.
To overcome these problems, some embodiments increase the number of switch ports on a switch without reducing the speed of its optical modules. More specifically, in some embodiments, instead of a single fiber optic cable, the optical transceiver module can be coupled to multiple parallel fiber optic cables, where each cable includes a single optical fiber or fiber bundle. In other words, rather than having a single input/output cable to facilitate a single switch port, the optical module now has multiple parallel input/output cables to facilitate multiple switch ports, thereby increasing the number of ports on the switch without reducing the speed of the optical module. Note that each individual switch port includes both input and output fiber optic cables.
Fig. 3A illustrates an exemplary interconnection among switches according to one embodiment. In fig. 3A, each link of each switch includes one optical module and each optical module includes two independent fiber optic cables. For example, switch 302 is equipped in its downlink with an optical module 304 coupled to two fiber optic cables, cables 306 and 308. Similarly, switch 312 is equipped with an optical module 314, and the input/output of optical module 314 is carried by two fiber optic cables, cables 316 and 318. Note that each fiber optic cable can include a single optical fiber or a bundle of optical fibers.
Fig. 3A also shows that two optical cables of an optical switch can be coupled to two optical cables of two different optical switches. For example, superior switch 302 can be individually coupled to inferior switches 322 and 324 via fiber optic cables 306 and 308. Similarly, the superior switch 312 can also be coupled to the inferior switches 322 and 324 separately via fiber optic cables 316 and 318. The network shown in fig. 3A is twice as large in scale as the example shown in fig. 2A, while leaving the speeds of the optical modules (e.g., optical modules 304 and 314) unchanged.
The scale of the network can be further increased by equipping each switch with a plurality of optical modules. Fig. 3B illustrates an exemplary interconnection among switches according to one embodiment. In fig. 3B, each switch includes two optical modules in one link (e.g., uplink or downlink), and each optical module includes two input/output optical cables. Thus, the links of each switch are now provided with four switch ports, thereby making it possible for the switch to be coupled to up to four other switches in the uplink or downlink. In the example shown in fig. 3B, the superior switch 342 is capable of being coupled in its downlink to the inferior switches 352, 354, 356 and 358 via four fiber optic cables of the switch 342. Similarly, the superior switch 344 can also be coupled to the same four inferior switches in its downlink via four fiber optic cables. The scale of the network has doubled compared to the example shown in fig. 2B, while keeping the switch fabric and optical module speed unchanged.
The scale of the network can be determined based on the number of optical modules per switch and the number of independent inputs/outputs per optical module. Fig. 4 illustrates an exemplary network with two stages of switches according to one embodiment. Each switch can be equipped with in its uplink or downlinkNEach of which can haveMEach of the individual inputs/outputs being a separate fiber optic cable. Note that the individual fiber optic cables may be a single fiber or a single bundle of multiple fibers. In the example shown in fig. 4, the optical modules included in the downlink of the upper switch 402 can be marked as module_0 (or mod_0) to module uN-1 (or MOD/u)N-1) and can mark the switch ports (i.e., input/output cables) of the optical module 404 as port_0 through port uM-1. As one can see from fig. 4, the downlink or uplink of each switch hasN×MPorts, thereby making it possible for the switch to be coupled to at most one of its downlinks or uplinksN×MAnd other switches.
In some embodiments, the switch can have various I/O capacities, such as 256×50 Gbps and 512×50 Gbps. The scope of the present disclosure is not limited by the type or capacity of the switch module. Similarly, optical modules equipped on the switch can have various speeds and conform to various types of form factors. In some embodiments, the optical module can have a speed of 200 Gbps or 400 Gbps. The optical module can have an eight-way small form-factor (OSFP), four-way small form-factor dual-density (QSFP-DD), or QSFP form factor. Furthermore, the Photophysical Medium Dependent (PMD) types used by the optical module can include SR8 (which refers to 8 pairs of multimode fibers), DR4 (which refers to 4 pairs of single mode fibers), and SR4.2 (which refers to 4 pairs of multimode fibers, with 2 wavelength channels per fiber).
In the example shown in FIG. 4, each switch stage includesN×MA plurality of switches, each switch coupled to a different stageN×MAnd switches, thereby maximizing the standardization of the network. In some embodiments, the upper level switch ports can be defined as @i 1 , j 1 , k 1 ) While the switch ports at the lower level can be defined as @i 2 , j 2 , k 2 ) Whereini、j、kThe numbers of the switch, the optical module on the switch and the output optical cable of the optical module are respectively referred to. The number (or sequence number) of the switch (i.e.,i) May range from 0 toN×M-1, the number of optical modules on the switch can range from 0 toN-1, while the number of the output cables on the optical module may range from 0 toM-1. Subscripts (1 or 2) refer to the switch level (up or down, respectively). In some embodiments, connections among the switch ports can be arranged using the following formulas:
wherein the method comprises the steps ofMRefers to the number of fiber optic cables per optical module and the% symbols indicate the integer division operation. According to the above formula, the leftmost switch port in the upper stage, i.e., port (0, 0, 0), should be connected to switch port (0, 0, 0), which is the leftmost port in the lower stage. Similarly, an adjacent switch port (i.e., port (0, 0, 1)) should be connected to switch port (1, 0, 0), meaning that it is connected to the second leftmost switch at the lower levelThe leftmost port. One can see that the above formula describes the connection shown in fig. 3B. Note that a symmetrical pattern can be observed, where connections from switch ports on one side of the top level can be a mirror image of connections from switch ports on the other side. In the example shown in fig. 3B, the connections from the left two switches on the top level are symmetrical with the connections from the right two switches. For example, the switch ports on the leftmost switch are sequentially coupled (left to right) to the leftmost ports on each lower level switch, and the switch ports on the rightmost switch are sequentially coupled (right to left) to the rightmost ports on each lower level switch. Such an arrangement ensures that the connections among all switches are maximized (i.e., each individual switch is connected to a maximum number of other switches) while keeping the overall length of the connection cable short.
The switch ports may also have different types of connection relationships other than those defined by the foregoing formulas, as long as the number of interconnected switches can be maximized. For example, there may be more or fewer switch stages. In the case of three switch stages, a mid-stage switch may have some ports coupled to an upper-stage switch and some ports coupled to a lower-stage switch. The scope of the present disclosure is not limited by the actual connection pattern among the switch ports.
Depending on the type of optical module used in the switch, the fiber optic cable can be assembled differently. More particularly, the fiber optic cable can be assembled differently depending on the type of optical interface provided by the optical module.
In some embodiments, the optical module may include an SN having 4 pluggable fiber interfaces such as manufactured by US convec, ltd. Of Hickory, north carolina TM (trademark of Senko Advanced Components, marlborough, ma) interface and MDC interface. Fig. 5A illustrates an exemplary optical interface of an optical transceiver module. In fig. 5A, the optical interface 500 of the optical module can include 4 pairs of fiber optic connectors, such as fiber optic connector pairs 502 and 504. In some embodiments, each fiber optic connector can comprise an LC-type connector. Each optical fiberThe connector can facilitate the coupling between a single optical fiber and an optical module. In some embodiments, each fiber pair (i.e., a fiber pair coupled to a connector pair) is capable of individually carrying transmitted and received optical signals. In the example shown in fig. 5A, a maximum of 8 individual optical fibers can be coupled to a 4-pair optical fiber connector.
In a conventional data center setting, the output of the optical module includes only a single fiber optic cable, which can include a bundle of optical fibers, with one half of the optical fibers carrying the transmitted optical signals and the other half carrying the received optical signals. Fig. 5B shows an exemplary optical interface configuration of an optical module according to the prior art. In fig. 5B, an optical module 510 on the switch has a single fiber optic cable 512. Note that although not shown in fig. 5B, a single fiber optic cable 512 can actually include four pairs of optical fibers. The fiber pairs stay together all the time because it represents the different directions of a single optical link. In the example shown in fig. 5B, the four pairs of fibers may be multimode fibers (MMF) or Single Mode Fibers (SMF). As previously discussed, a switch can be coupled to another switch via fiber optic cable 512. The optical module 510 shown in fig. 5B provides at most a single switch port for coupling to different switches. Fig. 5B also shows a front view, in phantom, of a connector 514 coupling a single fiber optic cable 512 to an optical interface 516 on an optical module 510. More specifically, connector 514 can include four separate fiber optic connectors, each having both an input port and an output port.
To increase the number of switch ports on each switch module, in some embodiments, individual fiber optic cables coupled to the optical modules can be divided into multiple groups. Fig. 5C illustrates an exemplary output configuration of an optical module according to one embodiment. In fig. 5C, eight optical fibers coupled to optical module 520 are divided into two separate groups, where each group of optical fibers forms an independent switch port, such as switch ports 522 and 524. More specifically, each fiber optic group can include a fiber optic cable representing a single optical link, and each fiber optic cable can include four optical fibers bundled together. These fibers can include single mode or multimode fibers. Because optical module 520 includes two independent switch ports (i.e., switch ports 522 and 524), a switch equipped with optical module 520 can be coupled to at least two other switches via the two switch ports (i.e., switch ports 522 and 524) of optical module 520. Fig. 5C also shows a front view of a connector 526 coupling the fiber optic cable 522 or 524 to the optical interface 528 of the optical module 520 in dashed circles. More specifically, the connector 526 can include two separate fiber optic connectors. In some embodiments, the optical interface 528 can include an SN, MDC, or duplex LC connector, and one can select the connector 526 based on the type of fiber optic connector located on the optical interface 528.
Fig. 5D illustrates an exemplary output configuration of an optical module according to one embodiment. In fig. 5D, eight optical fibers coupled to optical module 530 can be grouped into four separate groups, where each optical fiber group forms an independent switch port, such as switch port 532 or 534. More specifically, each fiber optic group can include a pair of optical fibers representing a single optical link. Each fiber within the pair carries an optical signal in one direction. These fibers can include single mode or multimode fibers. Because optical module 530 includes four independent switch ports, a switch equipped with optical module 530 can be coupled to at least four other switches via the four switch ports of optical module 530. Fig. 5D also shows a front view of connector 536 coupling the fiber pairs to optical interfaces 538 on optical module 530 in dashed circles. More specifically, connector 536 can comprise a separate fiber optic connector. In some embodiments, the optical interface 538 can include an SN, MDC, or duplex LC connector, and one can select the connector 536 based on the type of fiber optic connector located on the optical interface 538. For example, if the optical interface 538 includes four SN connectors, the connector 536 can include a corresponding SN connector.
Fig. 6A illustrates an exemplary arrangement of a plurality of fiber optic cables according to one embodiment. In fig. 6A, the fiber bundle 602 can include eight fibers (SMF or MMF) grouped into two groups. Each group can include four optical fibers bundled together as separate fiber optic cables (e.g., fiber optic cables 604 and 606). A four-core fiber optic connector (e.g., two SN, MDC, or duplex LC connectors grouped together) can be attached to each end of each fiber optic cable. For example, four-core fiber optical connectors 608 and 610 can be attached to the left and right ends, respectively, of fiber optic cable 604. Each four-core fiber optic connector can be used to couple one end of a corresponding fiber optic cable to an optical interface of an optical transceiver module. For example, connectors 608 and 610 can be coupled to optical interfaces 612 and 614, respectively. More specifically, the optical connectors or fiber optic connectors on the fiber optic cable mate with the corresponding optical interfaces such that the optical connectors can mate with the corresponding optical interfaces to achieve low loss coupling. For example, if the optical interface on the optical module is an SN, the optical connector on the corresponding cable will be an SN connector. Note that in a real-life implementation, fiber bundle 602 can be held together as a single bundle before it fans out at each end to allow separate fiber optic cables to be coupled to different switches. This can reduce the number of suspension cables in the data center.
In some embodiments, the optical module can include an eight-core fiber optical interface, allowing up to eight fibers to be coupled to the optical module simultaneously. By assembling eight optical fibers coupled to the same optical module into two separate cables in a manner similar to that shown in fig. 6A and by attaching separate connectors to the cables, some embodiments provide a single optical module with the ability to couple to two other optical modules without any change in the design of the optical interfaces on the optical modules. If a single optical module belongs to a particular switch and two other optical modules belong to two other different switches, this particular fiber arrangement can now allow the particular switch to be coupled to the two other different switches, thereby increasing the size of the network formed by the switches.
Fig. 6B illustrates an exemplary arrangement of a plurality of fiber optic cables according to one embodiment. In fig. 6B, the fiber bundle 622 can include eight fibers (SMF or MMF) grouped into four groups. Each group can include two optical fibers bundled together as separate fiber optic cables (e.g., fiber optic cables 624 and 626). A two-core fiber optic connector (e.g., SN, MDC, or LC connector) can be attached to each end of each fiber optic cable. For example, two-core fiber optical connectors 628 and 630 can be attached to the left and right ends of the fiber optic cable 624, respectively. Each two-core fiber optic connector can be used to couple one end of a corresponding fiber optic cable to an optical interface on an optical transceiver module. For example, connectors 628 and 630 can be coupled to optical interfaces 632 and 634, respectively. By assembling eight optical fibers into four separate fiber optic cables and by attaching separate optical connectors to each end of the fiber optic cables, some embodiments allow each end of the fiber optic bundle 622 to be coupled to up to four other optical modules, and thus, up to four other switches.
In some embodiments, an optical module equipped on a switch may have a multi-fiber push-pull (MPO) interface, where multiple fibers can be coupled to the optical module via the MPO interface. Furthermore, in order to group the plurality of optical fibers into individual groups, additional MPO connectors can be employed. Fig. 7A illustrates an exemplary output configuration of an optical module according to one embodiment. In fig. 7A, an optical module 700 has an MPO interface 702. A fiber bundle having an MPO connector 704 can be coupled to the optical module 700 via an MPO interface 702 and the MPO connector 704. In some embodiments, the MPO connector 704 may be a 16-core fiber MPO connector and the fiber bundle can include 16 SMFs or MMFs individually contained in its fiber jacket.
To achieve the desired number of switch ports supported by the optical module, in some embodiments, individual fiber bundles can be divided into multiple groups. In the example shown in fig. 7A, 16 fibers have been divided into two groups, where each group includes 8 fibers. Each set of eight fibers can also be coupled to a second stage MPO connector (e.g., eight-core fiber MPO connector 706 or 708), allowing these 16 fibers to be coupled to other optical modules via their MPO connectors. Note that the eight fibers in each group can also be divided into two subgroups, with each subgroup carrying signals in one direction. In some embodiments, the MPO connectors 706 and 708 can have a different nature than the MPO connector 704. For example, if the MPO connector 704 is male, the MPO connectors 706 and 708 may be female, allowing fiber optic cables having male connectors to be coupled to the MPO connectors 706 and 708. In general, the MPO connectors 704-708 are capable of acting as a converter that converts the 16-core fiber MPO interface 702 into two eight-core fiber MPO interfaces 706 and 708.
As one can see in fig. 7A, the optical module 700 now includes two separate ports (i.e., MPO connectors 706 and 708), allowing the optical module 700 to be coupled to up to two other optical modules. In other words, a switch equipped with the optical module 700 can be coupled to at most two other switches via the MPO connectors 704, 706, and 708. In this example, the high fiber count to low fiber count MPO converter (which includes MPO connectors 704-708) allows an optical module to have two independent inputs/outputs, thereby making it possible for the optical module to be coupled to at most two other optical modules.
Fig. 7B illustrates an exemplary output configuration of an optical module according to one embodiment. In fig. 7B, an optical module 720 has an MPO interface 722. The fiber bundle with MPO connector 724 can be coupled to the optical module 720 via MPO interface 722 and MPO connector 724. In some embodiments, the MPO connector 724 may be a 16-core fiber MPO connector and the fiber bundle can include 16 SMFs or MMFs. The 16 fibers attached to the MPO connector 724 can be grouped into four groups, where each group includes four fibers. A second stage MPO connector (e.g., four-core fiber MPO connector 726 or 728) can be attached to the other end of each group. In addition to four-core fiber MPO connectors, other types of connectors, such as a pair of duplex LC or SN connectors, can be used at the other end of each four-core fiber bundle. In the example shown in fig. 7B, a converter comprising a 16-core fiber MPO connector and four-core fiber connectors allows an optical module to have four independent switch ports, thereby making it possible for the optical module to be coupled to up to four other optical modules.
Fig. 8A illustrates an exemplary arrangement of a plurality of fiber optic cables according to one embodiment. In fig. 8A, the fiber bundle 802 can include sixteen fibers (SMF or MMF) grouped into two groups. Each group can include eight optical fibers bundled together as separate fiber optic cables (e.g., fiber optic cables 804 and 806). Eight-core fiber MPO connectors can be attached to each end of each fiber optic cable. For example, eight-core fiber MPO connectors 808 and 810 can be attached to the left and right ends of the fiber optic cable 804, respectively. Each eight-core optical network MPO connector is capable of coupling an optical cable to a corresponding MPO interface on an optical transceiver module.
Fig. 8B illustrates an exemplary arrangement of a plurality of fiber optic cables according to one embodiment. In fig. 8B, the fiber bundle 822 can include sixteen fibers (SMF or MMF) grouped into four groups. Each group can include four optical fibers bundled together as separate fiber optic cables (e.g., fiber optic cables 824 and 826). A four-core fiber optic connector (e.g., MPO or four-way LC connector) can be attached to each end of each fiber optic cable. For example, four-fiber MPO connectors 828 and 830 can be attached to the left and right ends, respectively, of the fiber optic cable 824. Each four-core fiber optic connector can facilitate coupling between an optical cable and a corresponding optical transceiver module. By assembling 16 fibers into four independent fiber optic cables, some embodiments allow one optical module to be coupled to up to four other optical modules, thereby increasing the size of the network by a factor of four.
Fig. 9 presents a flowchart illustrating an exemplary process for establishing a data center network, in accordance with one embodiment. During operation, a high performance data center switch can be selected (operation 902). The switch can be equipped with a number of optical transceiver modules that generally conform to a standard form factor (e.g., SFP, QSFP, QSFP-DD, OSFP, etc.). The PMD type of the optical transceiver module may be SR8, DR4 or SR4.2. The optical interface on the optical transceiver module may be SN, MDC or MPO. Each optical interface may allow coupling of a number of individual optical fibers. For example, an optical module can allow up to 16 individual optical fibers (SMF or MMF) to be coupled to its optical interface. The coupling between the optical fiber and the optical module can be achieved via an optical interface of the SN, MDC or MPO type.
Following the selection of the switch, a person can couple a number of individual fiber optic cables to one or more optical modules on the switch (operation 904). In some embodiments, multiple fiber optic cables can be coupled to a single optical module. Each cable can include a single optical fiber or a plurality of optical fiber bundles. For example, two cables, each cable comprising four separate optical fibers, can be coupled to an optical module having an eight-core optical fiber optical interface. Depending on the type of interface on the optical transceiver module, each fiber optic cable may be equipped with an appropriate optical connector. For example, if the optical transceiver module has an SN or MDC type optical interface, each fiber optic cable will have an SN or MDC connector. For example, if the optical module has an eight-core fiber SN interface, the two fiber optic cables can each have a four-core fiber double SN connector for insertion into the SN interface on the optical module. In different examples, four fiber optic cables can be coupled to an eight-core fiber SN interface on an optical module, where each fiber optic cable has an SN connector. On the other hand, if the optical transceiver module has an MPO interface, each fiber cable can also have an MPO connector, but the number of fibers is smaller. MPO converters similar to the converters formed by MPO connectors 704-708 shown in fig. 7A can facilitate coupling between fiber optic cables and optical transceiver modules.
After coupling the plurality of fiber optic cables to each optical module on the switch, one can couple the other end of each fiber optic cable to a different switch on another level according to a predetermined switch interconnection graph (operation 906). For example, each switch port (i.e., each individual fiber optic cable) can use a tripleti a , j a , k a ) Marking, wherein the subscriptaDesignating a switch stagei、jAndkswitch number, optical module number, and optical cable number are respectively specified. In some embodiments, there are two switch stages. Specific switch ports (e.g., ports #)i 1 , j 1 , k 1 ) The optical cable can be coupled to a predetermined switch port (e.g., port #)i 2 , j 2 , k 2 )). More specifically, the lower port can be determined based on the following formula:
after coupling all individual fiber optic cables from one switch to a different switch on the next level, one can determine if all switches are connected (operation 908). If not, a different switch is selected (operation 902) and the process repeats until each switch has been connected to the maximum number of other switches.
In general, embodiments of the present invention provide a solution for scaling up data center networks by increasing the number of switch ports supported by each switch without making changes to the switch fabric and optical transceiver modules. More specifically, to increase the number of ports per switch, some embodiments allow multiple independent fiber optic cables to be coupled to a single optical module, where each fiber optic cable represents a separate switch port. The individual fiber optic cables can be routed to other different switches, thereby connecting the switch to those other switches. Because the number of fiber optic cables coupled to a switch can be greater than the number of optical modules on the switch, some embodiments can significantly increase the number of ports per switch as compared to conventional approaches where a single fiber optic cable is coupled to each optical module, thus increasing the size of the network. In a particular scenario where there are two stages of switches, the coupling among the switch ports of the two stages can follow a predetermined pattern, which can ensure that each switch is coupled to a maximum number of other switches while keeping the total cable length short. The optical transceiver module can employ various types of optical interfaces. Thus, the fiber optic cable may employ different types of optical connectors. The scope of the present disclosure is not limited by the particular type of connector used by each fiber optic cable.
The foregoing description of the various embodiments has been presented only for the purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention. The scope of the embodiments described herein is defined by the appended claims.
Claims (14)
1. A communication system, comprising:
a first switch, wherein the first switch comprises one or more optical transceiver modules; and
a plurality of independent fiber optic cables coupled to respective optical transceiver modules of the first switch;
wherein the first switch comprisesNA plurality of optical transceiver modules, wherein each optical transceiver module is coupled toMA root independent fiber optic cable, and wherein the first switch is coupled to the communication systemM×NOther switches; wherein the communication system comprises at least two stages of switches; wherein the first switch is on a first stage and the corresponding port on the downlink of the first switch uses tripletsi 1 , j 1 , k 1 ) Marking by a mark, whereini、j、kRespectively representing a switch sequence number, an optical module sequence number and a port sequence number; and wherein the port [ ]i 1 , j 1 , k 1 ) Port coupled to an uplink of a second switch belonging to a second stagei 2 , j 2 , k 2 ) Whereini 2 = j 1 * M + k 1 ，j 2 = i 1 %MAnd (2) andk 2 = mod(i 1 , M)。
2. the communication system of claim 1, wherein the respective optical transceiver modules comprise one or more of:
an SN-based optical interface;
an MDC-based optical interface; and
multi-fiber push-pull MPO optical interface.
3. The communication system of claim 2, wherein the respective optical transceiver module comprises a plurality of SN or MDC based interfaces, and wherein the respective fiber optic cable comprises a SN or MDC based connector for coupling the respective fiber optic cable to the optical transceiver module, respectively.
4. The communication system of claim 2, wherein the respective optical transceiver module comprises an MPO optical interface, and wherein the respective fiber optic cable comprises an MPO connector or duplex LC connector for coupling the respective fiber optic cable to the optical transceiver module.
5. The communication system of claim 2, wherein the respective optical transceiver modules comprise MPO optical interfaces, and wherein the respective fiber optic cables are coupleable to the MPO optical interfaces via an MPO converter that converts a higher fiber count MPO interface to a lower fiber count MPO interface.
6. The communication system of claim 1, wherein each of the plurality of independent fiber optic cables is coupled to a different switch in the communication system.
7. The communication system of claim 1, wherein the respective switches in the communication system have an input/output (I/O) capacity of 256 x 50 Gbps (gigabits per second) or 512 x 50 Gbps.
8. The communication system of claim 7, wherein the respective optical modules have a speed of 200 Gbps (gigabits per second) or 400 Gbps.
9. A coupling mechanism for coupling among switches in a data center network, comprising:
a plurality of independent fiber optic cables coupled to respective optical transceiver modules of respective switches, wherein the plurality of independent fiber optic cables are coupled to a number of different switches in the data center network, wherein the respective switches compriseNA plurality of optical transceiver modules, wherein each optical transceiver module is coupled toMA root independent fiber optic cable, and whereinM×NA root independent fiber optic cable for coupling the respective switch into the data center networkM×NOther switches; wherein the data center comprises at least two stages of switches; wherein the corresponding port on the downlink of the first stage uses tripletsi 1 , j 1 , k 1 ) Marking by a mark, whereini、j、kRespectively representing a switch sequence number, an optical module sequence number and a port sequence number; and wherein the coupling mechanism is configured to cause the port [ ]i 1 , j 1 , k 1 ) Ports coupled to the uplink belonging to the second stagei 2 , j 2 , k 2 ) Whereini 2 = j 1 * M + k 1 ，j 2 = i 1 %MAnd (2) andk 2 = mod(i 1 , M)。
10. the coupling mechanism of claim 9, wherein the respective optical transceiver module comprises a plurality of SN or MDC based interfaces, and wherein the respective fiber optic cable comprises a SN or MDC based connector for coupling the respective fiber optic cable to the optical transceiver module, respectively.
11. The coupling mechanism of claim 9, wherein the respective optical transceiver module comprises an MPO optical interface, and wherein the respective fiber optic cable comprises an MPO connector or duplex LC connector for coupling the respective fiber optic cable to the optical transceiver module.
12. A method for coupling among switches in a data center network, the method comprising:
selecting a switch;
coupling first ends of a plurality of individual fiber optic cables to respective optical transceiver modules on the selected switch; and
coupling a second end of the plurality of independent fiber optic cables to a plurality of other switches in the data center network;
wherein the selected switch comprisesNAn optical transceiver module, wherein the method further comprises:
will beMA separate fiber optic cable coupled to each optical transceiver module; and
coupling the selected switch to the data center networkM×NOther switches; wherein the data center comprises at least two stages of switches; wherein the corresponding port on the downlink of the first stage uses tripletsi 1 , j 1 , k 1 ) Marking by a mark, whereini、j、kRespectively representing a switch sequence number, an optical module sequence number and a port sequence number; and wherein the method further comprises connecting the porti 1 , j 1 , k 1 ) Ports coupled to the uplink belonging to the second stagei 2 , j 2 , k 2 ) Whereini 2 = j 1 * M + k 1 ，j 2 = i 1 %MAnd (2) andk 2 = mod(i 1 , M)。
13. the method of claim 12, wherein the respective optical transceiver module comprises a plurality of SN or MDC based interfaces, and wherein coupling a first end of a respective fiber optic cable to the respective optical transceiver module comprises coupling a SN or MDC based connector on the respective fiber optic cable to a corresponding SN or MDC based interface on the respective optical transceiver module, respectively.
14. The method of claim 12, wherein the respective optical transceiver module comprises an MPO optical interface, and wherein coupling a first end of a respective fiber optic cable to the respective optical transceiver module comprises coupling an MPO connector or duplex LC connector on the respective fiber optic cable to the MPO optical interface.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2019/087082 WO2020227982A1 (en) | 2019-05-15 | 2019-05-15 | System and method for flexible optical interconnect in data centers |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113518980A CN113518980A (en) | 2021-10-19 |
| CN113518980B true CN113518980B (en) | 2024-03-01 |
Family
ID=73289793
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201980093429.0A Active CN113518980B (en) | 2019-05-15 | 2019-05-15 | System and method for flexible optical interconnect in a data center |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN113518980B (en) |
| WO (1) | WO2020227982A1 (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007109277A2 (en) * | 2006-03-21 | 2007-09-27 | The Boeing Company | Single fiber links for full duplex aircraft data network |
| CN101132286A (en) * | 2006-08-21 | 2008-02-27 | 丛林网络公司 | Multi-chassis router with multiplexed optical interconnects |
| CN103746941A (en) * | 2014-01-18 | 2014-04-23 | 浪潮集团有限公司 | Board-level interconnected big data all-in-one machine |
| CN104730652A (en) * | 2013-12-20 | 2015-06-24 | 中国航空工业集团公司第六三一研究所 | Optical interconnection structure for debugging and verifying |
| CN106062728A (en) * | 2014-01-31 | 2016-10-26 | 谷歌公司 | Systems and methods for increasing bandwidth in a computer network |
| CN206077583U (en) * | 2016-08-30 | 2017-04-05 | 宁夏仁智达科技有限公司 | A kind of cell digital monitor system |
| CN108369333A (en) * | 2015-12-11 | 2018-08-03 | 华为技术有限公司 | Modularization photon exchange board structure |
| CN109640196A (en) * | 2018-11-26 | 2019-04-16 | 中国人民解放军国防科技大学 | Wireless optical communication link reconfigurable system for data center |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1917714A (en) * | 2006-07-14 | 2007-02-21 | 清华大学 | Method for connecting antenna to signal process unit by exchange unit, and the exchange unit |
| US8842688B2 (en) * | 2009-01-20 | 2014-09-23 | The Regents Of The University Of California | Reducing cabling complexity in large-scale networks |
| US8503515B2 (en) * | 2010-01-14 | 2013-08-06 | Integrated Device Technology Inc. | High speed switch with data converter physical ports and processing unit |
| EP2671365A1 (en) * | 2011-01-31 | 2013-12-11 | Hewlett-Packard Development Company, L.P. | Cable harness switches |
| US9900101B2 (en) * | 2012-04-30 | 2018-02-20 | Hewlett Packard Enterprise Development Lp | Transceiver module |
| CN102710997A (en) * | 2012-05-23 | 2012-10-03 | 上海电信工程有限公司 | Fiber-to-the-home (FTTH) improvement method |
-
2019
- 2019-05-15 WO PCT/CN2019/087082 patent/WO2020227982A1/en active Application Filing
- 2019-05-15 CN CN201980093429.0A patent/CN113518980B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007109277A2 (en) * | 2006-03-21 | 2007-09-27 | The Boeing Company | Single fiber links for full duplex aircraft data network |
| CN101132286A (en) * | 2006-08-21 | 2008-02-27 | 丛林网络公司 | Multi-chassis router with multiplexed optical interconnects |
| CN104730652A (en) * | 2013-12-20 | 2015-06-24 | 中国航空工业集团公司第六三一研究所 | Optical interconnection structure for debugging and verifying |
| CN103746941A (en) * | 2014-01-18 | 2014-04-23 | 浪潮集团有限公司 | Board-level interconnected big data all-in-one machine |
| CN106062728A (en) * | 2014-01-31 | 2016-10-26 | 谷歌公司 | Systems and methods for increasing bandwidth in a computer network |
| CN108369333A (en) * | 2015-12-11 | 2018-08-03 | 华为技术有限公司 | Modularization photon exchange board structure |
| CN206077583U (en) * | 2016-08-30 | 2017-04-05 | 宁夏仁智达科技有限公司 | A kind of cell digital monitor system |
| CN109640196A (en) * | 2018-11-26 | 2019-04-16 | 中国人民解放军国防科技大学 | Wireless optical communication link reconfigurable system for data center |
Non-Patent Citations (1)
| Title |
|---|
| 数据中心光通信技术;谢崇进;;电信科学(05);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113518980A (en) | 2021-10-19 |
| WO2020227982A1 (en) | 2020-11-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8873967B2 (en) | Optical interconnection modules for hybrid electrical-optical networks | |
| US9097874B2 (en) | Polarity configurations for parallel optics data transmission, and related apparatuses, components, systems, and methods | |
| US9800472B2 (en) | Network node connection configuration | |
| US8270830B2 (en) | Optical network for cluster computing | |
| AU2018200618A1 (en) | Polarity scheme for parallel-optics data transmission | |
| US9154860B2 (en) | Optical interconnection assembly for spine-and-leaf network scale out | |
| WO2017088789A1 (en) | Line card frame, multi-frame cluster router, and message processing | |
| JPWO2006054703A1 (en) | Communication device for transmitting communication between slots of housing, wiring converter, and wiring method | |
| US20140369347A1 (en) | Increasing radixes of digital data switches, communications switches, and related components and methods | |
| CA2889023A1 (en) | Polarity scheme for parallel-optics data transmission | |
| US20230180424A1 (en) | Break out module system | |
| US11561352B2 (en) | High density optical I/O inside a data center switch using multi-core fibers | |
| Matsui et al. | Optical interconnect architecture for servers using high bandwidth optical mid-plane | |
| CN113518980B (en) | System and method for flexible optical interconnect in a data center | |
| Maniotis et al. | Application-oriented on-board optical technologies for HPCs | |
| WO2021228204A1 (en) | Electronic device | |
| CN211016457U (en) | Display control system and L ED display system | |
| TWI655470B (en) | Line optical communication component | |
| Hasharoni et al. | High BW parallel optical interconnects | |
| Sun et al. | High speed ethernet transmission over multicore fibers for data center applications | |
| AU2015296847A1 (en) | Polarity configurations for parallel optics data transmission, and related apparatuses, components, systems, and methods | |
| US11630274B2 (en) | High-density optical communications using multi-core fiber | |
| Lee | Market & Industrial Trends of Optical Interconnect | |
| CN116566488A (en) | Multi-core optical fiber wiring system of data center | |
| CN107132620A (en) | A kind of network structure based on rotation array waveguide grating device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |